Electrolytic apparatus.



.I. PFLEGER & F. OTT.

ELECTROLYTIC APPARATUS.

APPLICATION FILED ocr. 2. 191a.

1,186,937. T v Patented June 13, 191

- UNITED J'OHANNES IBFLEGER AND FRIEDRICH OTT, OF FRANKFORT-O N THE-MAIN, GERMANY,

ASSIGNOBS TO ROESSLER- AND HASSLACHER CHEMICAL COMPANY, YORK,

N. Y., A CORPORATION OF NEW YORK.

ELECTROLYTIC APPARATUS.

Specification of Letters Patent. 7

Patented June 13, 1916.

Application filed October 2, 1913. Serial No. 792,973.

To all whom it may concern Be it known that we, JOHANNES PFLEGER and FRIEDRICH OTT, subjects of the Emperor of Germany, and 'bothresidents of Frankfort-on-the--Main, -Germany, have invented certain new and useful Improvements in Electrolytic Apparatus, of which the following is a specification.

This invention relates to an improvement in electrolytic apparatus for the production of alkali metal, such as metallic sodium, from molten alkali haloids, such as sodium chlorid, and it refers particularly to the protection of an essential part of the apparatus against the harmful action of products generated in the process, such as chlorin gas for instance.

In a copending application filed June 16, 1913, Serial No. 774,039, wehave shown how to make the well known apparatus of Castner a. universal apparatus for the electrolytic production of alkali metal and to i use said apparatus especially for the utiliza- I such as sodlum tion of alkali-haloids, by protecting the outer surfaceof -the collector of the 'generated alkali metal by a material resistant to the action of the, products generated'at the anode;

We have found that one may use advantageously for the protection of the collector a solidified or homogenous layer of salt,

. such as sodium c'hlorid, or a mixture of salts",

chlo'rid and potassium chlorid, resistant to the products generated by the electrolysis.

In order to constantly maintain the protecting layer it is advisable in some cases to continuously or from time to time conduct off some heat from the metal collector. This is simply effected by partly constructing the collector as a-hollow cylinder, through which a cold gas or liquid current of an adequatestrength can be passed.

For the better understanding of ourinvention reference is made to the accompanying drawing, which represents a sectional elevation of a convenientform of apparatus for carrying our invention into effect.

The apparatus comprises a receptacle A, of iron or any suitable material, which serves as a container for the electrolyte as well as for the electrodes with the other appurtenances necessary thereto. The cathode 1, of lI'OIl or any other suitable material,

formed of a salt or mixture of salts,

receptacle 4' against the chlorin.

is entered preferably from below through the bottom of A. and extends upward into the vessel from which it. is suitably insulated. -The anode 2,preferably made of carcathode 1. The electrodes 1 and 2 are separated by a wire screen 3 which is connected with an iron receptacle/1, theupper end of which is closed by a lid.-

The electrolyte reaches somewhat below the rim of vessel A and leavesample space between anode and receptacle 4 into,which the chlorin gas escapes. The. outside of the receptacle 4, which is exposed to said chlorin gas, is covered with a layer 5, thus protecting Inside receptacle 4 the level of the electrolyte is somewhat higher than outside, owing to the low specific, gravity of the metal 6 as obtained by the process. The chlorin gas generated escapes" through pipe 7. The metal obtained by the electrolysis may be removed in any of the well known ways,

. either by dippin same out or by providing a contrivance metal.

The salt or mixture of salts is applied as a protective coat to the outside. of the -collector-by dipping the same, closed below by a detachable bottom, into the fused salt and removing it again quickly from the same, there may also be added to the salt such materials which with the prevailing working conditions are indifferent to the electrolytic products. It is not necessary that. the insulating layer be perfectly solidi or the drainage of said fied, as viscid homogeneous coats may also provide sufficient protection. The change'of physical state consisting in the transformation of the salt layer from the solid to the yiscid state or vice versa as well as the maintenance of the viscid state is effected in the simplest way byconducting off the re quired quantitiesof heat from the collector. The loss caused by-the quantities of heat thus conducted off in order to accomplish this purpose is practically of no importance. Conducting ofi'the heat oflers also the further advantages that the separated alkali metal iscooled off somewhat, which is de- .sirable in any case, whether one dips out the alkali metal or whether one drains same 0 Where we use the general expression salt in the claims, we mean to include both a mixture of salts as well as a single salt, and when we use the term solidified in the claims we mean to include the salt in such physical state that it will form a protective coating on the outer wall of the collector of the generated alkali metal,

whether the salt is actually solid or not.

We claim:

1. In an apparatus for the electrolysis of fused alkali salts, the combination with positive and negative electrodes having their working faces in close juxtaposition to each other, of'a gauze .or screen interposed between said electrodes, a superposed vessel or dome for receiving the separated metal Y and a halogen-resisting coating on the outer surface of said receiving vessel comprising solidified salt.

2:111 an apparatus for the electrolysis of fused alkali salts, the combination with positive and negative electrodes having their other, of a gauze or screen interposed between said electrodes, a superposed vessel or dome for receiving the separated metal and a chlorin-resisting coating on the outer surface of said receiving vessel comprising solidified sodium chlorid.

In testimony whereof we have signed our 1 names to this specification in the presence of two subscribing witnesses.

J OHANNES PFLEGER. FRIEDRICH OTT.

WVitnesses:

JEAN GRUND, CARL GRUND. 

